The University of Chicago, once a sports powerhouse, quit sports altogether. It did not die. One could even say it was improved. The Ivy League was a response to the professionalism in college sports. Football won’t die if its importance is diminished. Pro teams will just create their own minor leagues.
I think there’s a good argument to be made that colleges and universities should be institutions of higher learning, not the minor leagues for professional sports. That will probably be considered a medieval opinion nowadays.